1. Stay close to the center, it will be easier to aim. Keep the mouse near the middle of the screen. The closer the mouse pointer is to the bottom the greater the angle When you move the mouse. And the further away the smaller the angle when you shoot.
2. The more you fall before you shoot, the greater the distance you can climb.
3. When bouncing off the 2 sides can not be avoided, shoot as you go up. You should be able to catch a ledge sometimes on the way up. It will help to either slow or stop the bouncing and stabilize you.